A golf club head provided a hollow portion therein is known. Since the golf club head of this type is designed within a range of a limited mass, there is a tendency that a thin-wall sole portion would be designed due to increase in head volume. In order to obtain a thin-wall sole portion, a press forming product made of a thin rolled steel strip, for example, may be employed as a sole member. This aspect is advantageous in terms of productivity and cost. On the other hand, there is a problem that a golf club head having a thin-wall sole portion generates low hitting sound that many golfers do not prefer.
In order to improve the hitting sound of the golf club head, it has been proposed to provide a rib on the inner surface, which faces the hollow portion, of the sole portion (See, Patent Document 1).